wanna911

I am running -3.0 front and -2.5 rear camber on my car because it dramtically improves the handling, it also dramtically wears the inside edge of the tires.

Is there any way to get more even wear out of tires with camber this aggressive? The outer edges look untouched.

Do toe kits help this occurence, or is it a penalty of being able to turn better?

Geoffrey

Drive faster/harder. By your description, you either have too much camber for the tire, or too much camber for the lateral acceleration you are able to carry through the corner ie not driving the car hard enough.

What kind of car is it? What tires?

wanna911

996 TT on Sport Cups.

I did do a 400 mile mountain run on the tires as well, so the majority of the inner wear came at that time, but it was still pretty uneven. I just reversed the tires inside out so they wouldntv cord immediately.

I'm also running a bit of Toe in.

Mark in Baltimore

You've got too much camber. Dial it back and then you won't have to worry about wearing the inside edges. Why did you go with 3.5 degrees up front? Did you use a pyrometer to check temps?

wanna911

That was a typo, I'll change it now, it's only 3* in the front. I tried 2.5 it wouldnt allow me to take turn 1 at Road Atlanta in 4th gear without pushing, so I just jumped to 3. I guess I can start working my way back down now.


Though I'm doing Barber next and I would bet I get more out of the camber than I would at Road Atlanta.


I definitely need a pyrometer though.

APKhaos

Ideal camber for track setup is not even close to compatible with 400 mile street drives.
If you are doing a lot of street driving and a few track events, it might be worth getting yourself a camber gauge and leaning to set the camber for your track events and to reset it for street use.

As Mark said, tire temps are the most reliable diagnostic for optimal track setup.

Bryan Watts

Too much toe will often wear tires quicker than too much camber. Tried 0 toe up front? BMW's work well like that, but I'm not sure how a 911 reacts.

dbryant61

I've gotten some argument on this, but I have fount a tiny bit of toe-out (1/8" total) up front, and a little more toe-in (3/16-1/4" total) in the rear is a great setup. It makes turn-in more immediate and carries well through the turns. It does make it a little skittish on the highway, but I am doing less street driving each year. This may not apply to later 911s - YMMV.

+1 on "You need a pyrometer".

Circuit Motorsports

I found this to be the case in one of my old cars.

The toe wore the tires out like crazy and the camber didn't wear the inner edge too much.

wanna911

I bought my car in december of 06 with 27,900 miles, it now has 32500 miles, probably 1200 miles or 25% has been done on the street, I do an occasional mountain run, but from now on I'll go ahead and get an extra aligment and take the camber out for those times and re align it for the next track event.

I will buy a pyrometer in the next couple of weeks.

I was running toe in because it helped with braking, but I'm moving to toe out to help turning as that is a bigger concern. I'm going to keep -3 for barber since there are so many turns and it's not a high speed track, but when I go to VIR the following weekend, I may change to 2.8 or so.

Thanks for the input guys.


But while we are on the subject, I know it varies by tire, but what are safe temperature deltas for the pyrometer? And do you take the outside edge temp, inside edge temp and middle, or some other series of points to determine.

Is it possible to be within the operable temperature range and not get the desired handling affect or even wear? Or generally does the camber/tire wear and temperatures balance out? Meaning if I am running too hot on the inside edge, that means I'm not using all of the tire anyways during cornering so a decrease in camber wont significantly affect the handling but will even the tire wear?

KRA993tt

Have you tried less adjustment with camber and more with sway bars? You may be able to get the handling you want at the track with easier to adjust sway bars. I would guess that anything over about a 1-1.5 degrees negative camber on the road and you are going to see unwanted tire wear. My .02

Bull

As stated, road driving is the killer with proper track alignments, particularly with heavy cars.

wanna911

My sways are full stiff, 24 mm H&R in the rear, I kept it stock in the front, would like to go even less stiff in the front than stock if that's possible.




I figured it would be, but mine did better than my buddies 997 GT3. His car only has a couple thousand miles on it as well, and none of them were track miles, he corded the inside his on the same mountain run with factory GT3 settings. Of course he has 19's and mine are 18's.

I know that street driving and track alignment dont mix, but I mentioned before that the tread wear was moderately uneven before, now its EXTREMELY uneven.

todinlaw

Tony, two questions. do you know what the stock camber is on the GT3. Also regarding getting your own camber gauge to DIY do you need a lift to get it done?

Mark in Baltimore

I am far from the Road Atlanta track mastah (only been there once, at last year's club race, and absolutely loved it, BTW), but if you're pushing in T1, maybe you have some other balance issues. That turn is fast; I like having some understeer so I can go in deeper and harder. If you've got a big a** H&R sway in the rear and a stock bar up front, it sounds like you love oversteer. Is there that much understeer with a 996TT? I've instructed a student in one and never noticed an excessive amount of push.